The present invention is directed to telecommunication networks, and especially to telecommunication networks involving calls from mobile calling instruments to special number service stations. An example of such a call from a mobile calling instrument to a special number service station is a call from a cellular phone, from a Voice over Internet Protocol (VoIP) calling instrument or from another wireless or otherwise mobile device to an emergency service station such as a Public Safety Answering Point (PSAP) in an emergency service call system.
An emergency service call system, commonly known in the United States as an E9-1-1 System, will be employed herein as an exemplary preferred embodiment of the present invention. Other special number systems are deployed and would benefit from the present invention. Examples of such other special number systems include (by way of example and not by way of limitation) non-emergency police or fire call systems, telephone network maintenance call systems and commercially established special numbers (e.g., “dial ‘GOTIX’ on your AT&T Wireless phone for tickets”).
A basic 9-1-1 (Emergency Services) System provides for programming with special 9-1-1 software a telephone company end office (also known as a “central office” or a “Class 5 office”) to route all 9-1-1 calls to a single destination. The single destination is termed a Public Safety Answering Point (PSAP). In such an arrangement, all telephones served by the central office would have their 9-1-1 calls completed to the PSAP. However, the areas served by respective telephone company central offices do not line up with the political jurisdictions that determine the boundaries for which PSAP may be responsible. That is, a municipal fire department or police department may geographically include an area outside the area served by the central office, a condition known as underlap. Likewise, the municipal fire or police department may encompass an area of responsibility that is less expansive than the area served by the central office, a situation known as overlap. Further, the original basic 9-1-1 systems did not provide any identification of the caller; the PSAP human operator had to obtain such information verbally over the line after the call was connected. The major shortcoming of the basic 9-1-1 systems was that they could not support interconnection to other telecommunication providers such as independent telephone service companies, Alternate Local Exchange Carriers (ALECs), or wireless carriers. The “basic” nature of the basic 9-1-1 system also indicates that the system does not have Automatic Location Information (ALI) capability or Automatic Number Identification (ANI) capability with a call back capability.
Similar abbreviated number systems are in place for handling emergency service calls in countries other than the United States. The abbreviated number system established in Canada is the foreign system most similar to the system established in the United States. There are other abbreviated number calling systems in place in the United States and abroad for such purposes as handling municipal information and services calls (3-1-1) and for other purposes. All of these special or abbreviated number call systems that have geographic-based content suffer from similar shortcomings in their abilities to automatically place incoming calls to an action-response facility geographically proximate to the locus of the caller. It is for this reason that the 9-1-1 emergency call system of the United States is employed for purposes of this application as a preferred embodiment of the system and method of the present invention.
Automatic Number Identification (ANI) is a feature for 9-1-1 services that allows the caller's telephone number to be delivered with the call and displayed at the PSAP. This ANI feature is sometimes referred to as Calling Party Number (CPN). The feature is useful for identifying the caller and, if the caller cannot communicate, for callback. A signaling scheme known as Centralized Automatic Message Accounting (CAMA), originally used to identify the originator of a long distance call for billing purposes, was adapted to facilitate ANI delivery to the PSAP.
The availability of the caller's telephone number to the PSAP (the ANI feature) led quickly to providing the caller's name and address as well. This was straightforwardly accomplished using the subscriber information stored by telephone companies based upon telephone number since the 1980's. New equipment at the PSAP enabled queries of an Automatic Location Information (ALI) database using the caller's number provided by the ANI feature to ascertain name and address information. The ALI databases are typically maintained by the respective telephone company serving the PSAP. This was an improvement, but a problem still remained where several telephone company central offices served a town or county. Other problems also developed with the growing volume of mobile callers using wireless phones, satellite phones and communications over the Internet. Information regarding the locus of the origin of the call merely identified the locus where the call entered the wireline network; even such limited location information is not always provided. No indication was presented to identify the geographic location of such mobile callers.
As the situation of multiple central offices serving a PSAP occurred more frequently, it was clear that it was inefficient to build communication trunks from several central offices to a PSAP. As a result the 9-1-1 Tandem was developed. With that equipment, trunks from central offices are concentrated at a tandem office (a 9-1-1 Tandem) from which a single trunk group serves a given PSAP. Often a 9-1-1 tandem comprises an otherwise common Class 5 telephone system end office (EO), with added software to configure it for 9-1-1 operations. Such concentration of trunks reduces size and cost of PSAP equipment. The tandem is a telephone company switch that provides an intermediate concentration and switching point. Tandems are used for many purposes, including intra-LATA (Local Access and Transport Area) toll calls, access to other local exchange carriers (LECs), and access to long distance carriers and telephone operators.
A significant development in 9-1-1 services has been the introduction of Enhanced 9-1-1 (E9-1-1). Some of the features of E9-1-1 include Selective Routing, ANI, ALI, Selective Transfer and Fixed Transfer. Selective Transfer enables one-button transfer capability to Police, Fire and EMS (Emergency Medical Service) agencies appropriate for the caller's location listed on the ALI display. Fixed Transfer is analogous to speed dialing. Enhanced 9-1-1 services also permit provisioning supplemental data or information regarding calling parties, such as allergies to medications, presence of pets, infants or handicapped persons at the premises or similar information useful to responding to emergency service personnel.
Selective Routing is a process by which 9-1-1 calls are delivered to a specific PSAP based upon the street address of the caller. Selective Routing Tandems do not directly use address information from the ALI database to execute decisions regarding which PSAP to connect. Recall that emergency services (Police, Fire and EMS) are typically delivered on a municipality basis. Often there will be one Police Department (e.g., municipal, county or state), but there may be several Fire Departments and EMS Agencies. The town will be divided into response areas served by each respective agency. The response areas are overlaid and may be defined as geographic zones served by one particular combination of Police, Fire and EMS agencies. Such zones are referred to as Emergency Service Zones (ESZ). Each ESZ contains the street addresses served by each type of responder. The ESZs are each assigned an identification number (usually 3–5 digits), known as Emergency Service Numbers (ESN).
The Assignment of ESZs and corresponding ESNs enables the compilation of selective routing tables. The street addresses are derived from a Master Street Address Guide (MSAG), a database of street names and house number ranges within associated communities defining Emergency Service Zones (ESZs) and their associated Emergency Service Numbers (ESNs). This MSAG enables proper routing of 9-1-1 calls by the 9-1-1 Tandem; this is Selective Routing as implemented in an E9-1-1 system. Thus, the telephone company must have an MSAG valid address to be assigned the appropriate ESN for selective routing purposes and that information must be added to the E9-1-1 ALI database. It is by using such information that the selective routing capability of the Selective Routing Tandem can properly route an E9-1-1 call to the correct PSAP. If the information is not available in the ALI database, the record is placed into an error file for further manual handling.
A portion of the ALI database may be loaded into a Selective Routing Data Base (SRDB) for use by the 9-1-1 Tandem. The SRDB may be located in the Tandem, in an adjunct processor, or in the ALI database.
Reliability is a very important factor considered in designing 9-1-1 systems. One approach to providing reliability is to provide diversely routed trunk groups from each central office to its respective 9-1-1 Tandem. Preferably, each trunk group is large enough to carry the entire 9-1-1 traffic load for the respective central office. However, some systems are designed with less than full traffic capacity on trunk groups to “choke” or “congestion manage” incoming calls to a tandem in order to avoid overloading a PSAP. In some arrangements, parallel 9-1-1 Tandems are provided so that a central office has capable 9-1-1 Tandem ready for use (albeit with 50% call handling capacity) without interruption if one of the 9-1-1 Tandems fails. Switched bypass to an alternate 9-1-1 Tandem, commonly using digital crossover switches, is another approach to providing reliability in 9-1-1 systems.
Another approach to providing redundancy and robustness for a 9-1-1 system is the employment of Instant Network Backup (INB). Using INB, if a call does not complete to the 9-1-1 network for any reason (e.g., trunk failure, facility problem, 9-1-1 Tandem failure or port failure), the INB takes over and completes the call to a predesignated 7- or 10-digit number. Using this INB alternate path, ANI and ALI information are not delivered, but the call is completed to a local public safety agency, usually the local PSAP.
The interface between Operator handled calls and a 9-1-1 system is addressed in several ways. One system provides a direct connection between an Operator Tandem and the 9-1-1 Tandem. The operator forwards the call with the caller's ANI to the 9-1-1 Tandem. The 9-1-1 Tandem treats the call as though the caller had dialed the call. A second way to effect the desired interface is by using pseudo numbers. A pseudo number is a number that, when dialed, will reach a specific PSAP as a 9-1-1 call. Pseudo numbers have some special ALI information associated with them; for example, there may be a pseudo number associated with each municipality in a state. Dialing the pseudo number, usually from outside the LATA (Local Access and Transport Area), will generate a 9-1-1 to the PSAP for that municipality. The ALI display will indicate that it is a third party conference call from an unknown address in that town. The caller is not identified, but the call goes to the PSAP where the caller is believed, or claims, to be. Pseudo numbers are useful for Alternate Local Exchange Carrier (ALEC) or Competitive Local Exchange Carrier (CLEC) operators who may be located anywhere in the country.
A third method for effecting an interface for operator handled calls with a 9-1-1 system is through the Public Switched Telephone Network (PSTN), dialing the directory number for the PSAP. This is often referred to as the “back door” number by ALEC and CLEC operators.
The advent of wireless communications and other mobile phone capabilities (e.g., VoIP phones) has further exacerbated the difficulty of ascertaining caller location in telecommunication systems. The “patchwork” solutions described above regarding 9-1-1 systems have been mirrored in other special or abbreviated number systems to a significant extent. The “patchwork” solutions have created a capability-limited telecommunication system that cannot ascertain geographic information as fully or as easily as it should for all types of callers. This capability limitation has been especially felt in connection with calls made from mobile telephone instruments. The system is overly dependent upon human intervention to properly route calls to appropriate receivers, such as a proper PSAP. New modes of communication, such as Voice Over Internet Protocol (VoIP) and wireless communication instruments including wireless phones, wireless Personal Computers (PCs), wireless Personal Digital Assistant (PDA) devices and other mobile instruments, further contribute to telecommunication traffic not identifiable regarding geographic origin using present telecommunication routing systems.
Similar limitations will likely occur in other abbreviated number, or other special number, telephone systems handling location-based calls with resulting adverse limitations. Other such abbreviated number systems include emergency call systems in countries other than the United States, abbreviated number calling systems for reaching telephone maintenance services, abbreviated number calling systems for municipal information and services, and similar systems.
Provisioning of supplemental information to a special number service station (e.g., a PSAP in an emergency service call system) regarding a call originating from a mobile calling instrument is particularly difficult. Even with precise location information regarding locus of the origin of the call, such as would be available, for example, when the calling instrument has a Global Positioning System (GPS) capability, does not fulfill the need for availability of supplemental information regarding the calling party. Such supplemental information may include (by way of example and not by way of limitation) medical needs of the caller like allergies to medicines, or a request to notify specified personnel in the case of an emergency, or other information unique to the calling party that may be useful to responding emergency personnel. Other wireless systems, such as Automatic Collision Notification systems (ACN; one such system is referred to as ONSTAR™) may find it useful to alert responding emergency personnel that an infant or an invalid may be in an automobile involved in an accident. No systems are presently available to effect provisioning such supplemental information to a responding service station (e.g., a PSAP) for mobile instrument-originated calls. Mobile instrument-originated calls may include mobile telephone devices, wireless Personal Computers (PCs), wireless Personal Digital Assistant devices (PDAs), pager devices and other wireless-communication capable devices, whether capable of one-way or two-way communication. The present invention is also beneficial for other calling equipment having no particular fixed position, such as Voice over Internet Protocol phone devices (VoIP phones).
There is a need for a system and method for providing particular information relating to a caller placing a call from a mobile calling instrument to a special number service station in a telecommunication network.